氮化铝基导热复合材料的制备及性能研究

Preparation and Properties of AlN-Based Thermal Conductive Composites

摘要:

本文采用AlN角形粉和AlN球形粉为填料，以PDMS为有机基体，来制备不同固含量的导热复合材料，研究了AlN形态、AlN填充分数及粉体表面改性等对导热复合材料粘度及热导率的影响。研究结果表明，与角形AlN相比，球形AlN粉体可显著降低复合材料的粘度，因而有利于获得更高的填充分数和更大的复合热导率。利用KH570对AlN粉体进行表面改性，有利于降低界面热阻，提高复合热导率，改性浓度为2.0wt%时，复合材料热导率可提高22.5%。

Abstract:

In this study, thermal conductive composites with various filling fraction were prepared using angular and spherical AlN powders as fillers and PDMS as organic matrix. The influence of particle morphology, filling fraction and surface treatment on the viscosity and thermal conductivity of composites were deeply investigated. The results indicated that the AlN spherical powders could significantly reduce the viscosity of composites compared with the AlN angular powders, which was in favor of obtaining higher filling fraction and larger composite thermal conductivity. In addition, the surface treatment of AlN powders with KH570 were beneficial to reduce the interface thermal resistance and improve the composite thermal conductivity. When the concentration of KH570 was 2.0wt%, a highest composite thermal conductivity were obtained, which was ~22.5% higher than that of untreated fillers.